New data could lead doctors to use Johnson & Johnson and Bayer's blood thinner Xarelto to prevent heart attacks in some patients, leading to a significant sales boost. In a note to investors earlier this month, Credit Suisse analyst Divan Vamil predicted that a successful result could increase sales of the drug by $1.5 billion in the U.S. alone.

Well, the results are a success, although they come with the same trade-off as any use of a blood thinner: more bleeding.